Plugs used to seal an end portion of a fluid passing passage in a crankshaft have been used for decades. The end portion is plugged to force lubricating fluid, such as lubricating oil, to flow through other intersecting fluid passing passages for the purpose of delivering pressurized lubricating fluid to engine bearings, such as, main and rod journal bearings.
It has been found that in the fluid passing passage, a dead space normally exists between the plug and an intersecting juncture of a connecting passage. This dead space tends to collect operating residue of the type normally associated with engine operation and wear. This ultimately results in a buildup of this residue between the plug and the intersecting juncture. Should this build up become excessive, the intersecting passage may become blocked. This restricts the flow of lubricating fluid to at least the engine bearings and premature wear of the bearings and associated components.
In the past, it has been a common practice in some engines to be able to remove the plug and clean the passage when appropriate. This requires that the engine is substantially disassembled in order to gain full access the crankshaft. This results in engine down time and in a loss of engine productivity. Such maintenance is also very expensive.
Sealing plugs are normally disposed in the bore and held in place by pressing, screw threads, or other well known mechanical maintaining arrangements. Plugs held in by pressing are difficult and often impossible to remove. It is often necessary to remove the crankshaft from the engine in order to remove the pressed in plug. In some cases the crankshaft requires machining or replacement because of damage caused by plug removal.
Plugs connected by screw threads are not acceptable in some engines as they tend to become unscrewed during engine operation. This is particularly true in engines with an unbalanced firing order, for example, an engine with a nine throw crank. In engines such as this, a large internal bending order causes vibration. This causes a working out of the plug during operation.
Plugs that are held in place by snap rings and the like tend to rattle around in the bore in which they are disposed. This causes wear of the crankshaft within the bore and results in a leakage path for the lubricating fluid.
It is desirable to eliminate the dead space, to provide a plug that is rattle free and one that is easily removable from the crankshaft without requiring excessive engine disassembly.
The present invention is directed to overcoming one or more of the problems as set forth above.